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Genital Tubercle
A genital tubercle, phallic tubercle, or clitorophallic structure is a body of tissue present in the development of the reproductive system of amniotes. It forms in the ventral, caudal region of mammalian embryos of both sexes, and eventually develops into a primordial phallus. In the human fetus, the genital tubercle develops around week four of gestation, and by week nine, becomes recognizably either a clitoris or penis. This should not be confused with the sinus tubercle which is a proliferation of endoderm induced by paramesonephric ducts. Even after the phallus is developed (either a penile shaft or clitoral shaft), the term genital tubercle remains, but only as the terminal end of it, which develops into either the glans penis or the glans clitoridis. In the development of the male fetus, the two sides of the tubercle approach ventrally forming a hollow tube that encloses the male urethra. The two glans wings merge in the midline forming the septum glandis. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive System
The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are also important accessories to the reproductive system. Unlike most organ systems, the sexes of differentiated species often have significant differences. These differences allow for a combination of genetic material between two individuals, which allows for the possibility of greater genetic fitness of the offspring.Reproductive System 2001 Body Guide powered by Adam Animals In mammals, the major organs of the reproductive system include the external gen ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoderm
Endoderm is the innermost of the three primary germ layers in the very early embryo. The other two layers are the ectoderm (outside layer) and mesoderm (middle layer). Cells migrating inward along the archenteron form the inner layer of the gastrula, which develops into the endoderm. The endoderm consists at first of flattened cells, which subsequently become columnar. It forms the epithelial lining of multiple systems. In plant biology, endoderm corresponds to the innermost part of the cortex ( bark) in young shoots and young roots often consisting of a single cell layer. As the plant becomes older, more endoderm will lignify. Production The following chart shows the tissues produced by the endoderm. The embryonic endoderm develops into the interior linings of two tubes in the body, the digestive and respiratory tube. Liver and pancreas cells are believed to derive from a common precursor. In humans, the endoderm can differentiate into distinguishable organs after 5 w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clitorophallus
Clitorophallus is a term used to refer to the penis or clitoris. It is typically used when the clitorophallus is of a size where it is not clear as to whether it is a penis or a clitoris ( ambiguous genitalia). Often it is a matter of size that leads people to differentiate it as a penis or a clitoris, though placement of the urethral meatus may also play a part. During sexual development of an embryo, the clitorophallus is typically referred to as the "genital tubercle". The stages of development between male and female embryos are identical until around the 9th week post-fertilization, thus the clitorophallus is not distinguishable as a penis or a clitoris. The position of the urethra is also likely to vary (see Hypospadias and Epispadias). These occasions may occur when someone is intersex, which is also referred to as "disorders of sex development" or "DSD". The term may also be used when referring to the phallus of a transsexual A transsexual person is someone w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of androgenic hair, body hair. It is associated with increased aggression, sex drive, Dominance hierarchy, dominance, courtship display, and a wide range of behavioral characteristics. In addition, testosterone in both sexes is involved in health and well-being, where it has a significant effect on overall mood, cognition, social and sexual behavior, metabolism and energy output, the cardiovascular system, and in the prevention of osteoporosis. Insufficient levels of testosterone in men may lead to abnormalities including frailty, accumulation of adipose fat tissue within the body, anxiety and depression, sexual performance issues, and bone loss. Excessiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone primarily involved in the growth and repair of the prostate and the penis, as well as the production of sebum and body hair composition. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues including the prostate gland, seminal vesicles, epididymides, skin, hair follicles, liver, and brain. This enzyme mediates reduction of the C4-5 double bond of testosterone. DHT may also be synthesized from progesterone and 17α-hydroxyprogesterone via the androgen backdoor pathway in the absence of testosterone. Relative to testosterone, DHT is considerably more potent as an agonist of the androgen receptor (AR). In addition to its role as a natural hormone, DHT has been used as a medication, for instance in the treatment of low testosterone levels in men; for information on DHT as a medication, see the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulval Vestibule
The vulval vestibule (also known as the vulvar vestibule or vestibule of vagina) is the part of the vulva between the labia minora. At the innermost part are the vaginal introitus and urinary meatus. The Bartholin's and Skene's glands each have two openings to the vestibule on the inside. The outer edge, marked by a coloration difference in the tissues, is called Hart's line, named after David Berry Hart. The vestibule represents the distal end of the urogenital sinus of the embryo.''Manual of Obstetrics''. (3rd ed.). Elsevier. pp. 1–16. . Structure Structures opening in the vulval vestibule are the urethra ( urinary meatus), vagina, Bartholin's glands, and Skene's glands. The external urethral orifice is placed about 25–30 millimetres (1–1.2 in) behind the clitoris and immediately in front of that of the vagina; it usually assumes the form of a short, sagittal cleft with slightly raised margins. Nearby are the openings of the Skene's ducts. The vaginal ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Labia Minora
The labia minora (Latin for 'smaller lips', : labium minus), also known as the inner labia, inner lips, or nymphae, are two flaps of skin that are part of the primate vulva, extending outwards from the inner Vagina#Vaginal opening and hymen, vaginal and Urethral meatus, urethral openings to encompass the Vulval vestibule, vestibule. At the glans clitoridis, each labium splits, above forming the clitoral hood, and below the frenulum of the clitoris. At the bottom, the labia meet at the ''labial commissure''. The labia minora vary widely in size, color and shape from individual to individual. The labia minora are situated between the labia majora and together form the labia. The labia minora are Homology (biology), homologous to the penile raphe and ventral penile skin in males. Structure and functioning The labia minora extend from the clitoris obliquely downward, laterally, and backward on either side of the vulval vestibule, ending between the bottom of the vulval vestibule and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Septum Glandis
The septum glandis, also septum of the glans, refers to the fibrous partition of the ventral aspect of the glans penis that separates the two glans wings in the ventral midline. The septum extends from the urethral meatus through the glanular urethra ( fossa navicularis) and ends in the tunica albuginea of the human penis. Externally it is attached to the frenulum which extends lower on the neck of the penis. The septum glandis results during the embryonic development of the male fetus as the two sides of the genital tubercle merge in the midline without fusing, to form a hollow tube that encloses the male urethra. The two sides of the preputial lamina that will become the prepuce approach on the underside and remain separated by a thin tissue of mesenchyme that will form the frenulum. Ventrally, the two wings of the corona do not fully attach to each other, remaining separated at the subglanular level. See also * Septum of the penis *Scrotal septum The septum of scr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Male Urethra
The urethra (: urethras or urethrae) is the tube that connects the urinary bladder to the urinary meatus, through which placental mammals urinate and ejaculate. The external urethral sphincter is a striated muscle that allows voluntary control over urination. The internal sphincter, formed by the involuntary smooth muscles lining the bladder neck and urethra, receives its nerve supply by the sympathetic division of the autonomic nervous system. The internal sphincter is present both in males and females. Structure The urethra is a fibrous and muscular tube which connects the urinary bladder to the external urethral meatus. Its length differs between the sexes, because it passes through the penis in males. Male In the human male, the urethra is on average long and opens at the end of the external urethral meatus. The urethra is divided into four parts in men, named after the location: There is inadequate data for the typical length of the male urethra; however, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glans Penis
In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin ''glans'' meaning "acorn") is the bulbous structure at the Anatomical terms of location#Proximal and distal, distal end of the human penis that is the human male's most sensitive erogenous zone and primary anatomical source of Human sexuality, sexual pleasure. The glans penis is present in the male reproductive system, reproductive organs of humans and most other mammals where it may appear smooth, spiny, elongated or divided. It is externally lined with Mucosa, mucosal tissue, which creates a smooth texture and glossy appearance. In humans, the glans is located over the distal ends of the Corpus cavernosum penis, corpora cavernosa and is a continuation of the Corpus spongiosum (penis), corpus spongiosum of the penis. At the summit appears the urinary meatus and at the base forms the Corona of glans penis, corona glandis. An elastic band of tissue, known as the Penile frenulum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Of Penis
The body or shaft of the penis is the free portion of the human penis that is located outside of the pelvic cavity. It is the continuation of the internal root, which is embedded in the pelvis and extends to the glans. It is made up of the two corpora cavernosa and the corpus spongiosum on the underside. The corpora cavernosa are intimately bound to one another with a dorsally fenestrated septum, which becomes a complete one before the penile crura. The body of the penis is homologous to the female clitoral body. Structure The body of the penis is suspended from the pubic symphysis. It has two surfaces; the ''dorsal'' and the ventral or ''urethral''. The penile raphe runs on its ventral surface. The body is surrounded by a bi-layered model of tunica albuginea in which a distal ligament buttresses the glans penis and plays an integral role to the penile fibroskeleton, and the structure is called "os analog", a term coined by Geng Long Hsu in the Encyclopedia of Reproduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
